首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Since the Hawaiian Islands have never been connected to other landmasses, the great variety of plants in Hawaii must be a result
Since the Hawaiian Islands have never been connected to other landmasses, the great variety of plants in Hawaii must be a result
admin
2013-01-28
96
问题
Since the Hawaiian Islands have never been connected to other landmasses, the great variety of plants in Hawaii must be a result of the long-distance dispersal of seeds, a process that requires both a method of transport and an equivalence between the ecology of the source area and that of the recipient area.
There is some dispute about the method of transport involved. Some biologists argue that ocean and air currents are responsible for the transport of plant seeds to Hawaii. Yet the results of flotation experiments and the low temperatures of air currents cast doubt on these hypotheses. More probable is bird transport, either externally, by accidental attachment of the seeds to feathers, or internally, by the swallowing of fruit and subsequent excretion of the seeds. While it is likely that fewer varieties of plant seeds have reached Hawaii externally than internally, more varieties are known to be adapted to external than to internal transport.
The author of the passage is primarily concerned with ______.
选项
A、discussing different approaches biologists have taken to testing theories about the distribution of plants in Hawaii
B、discussing different theories about the transport of plant seeds to Hawaii
C、discussing the extent to which air currents are responsible for the dispersal of plant seeds to Hawaii
D、resolving a dispute about the adaptability of’ plant seeds to bird transport
答案
B
解析
本文作者主要讨论各种有关把植物种子输送到夏威夷的理论。首先,生物学家们认为,由于海洋和气流的缘故,植物的种子被输送到夏威夷;其二,漂浮实验以及气流低温实验结果对有关假设提出质疑;其三,鸟类最有可能把种子带到夏威夷。
转载请注明原文地址:https://kaotiyun.com/show/hu1O777K
0
考博英语
相关试题推荐
Thepossibilitiesofanautumnelectioncannotbe______.
Keysshouldneverbehiddenaroundthehousesincethieves______knowwheretolook.
Concernwithmoney,andthenmoremoney,inordertobuytheconveniencesandluxuriesofmodernlife,hasbroughtgreatchanges
Montaigne’sholdonhisreadersarisesfrommanycauses.Thereishisfrankandcuriousself-delineation.Thatinterests,becaus
Researcherswhorefusetosharedatawithothersmay【51】otherstowithholdresultsfromthem,【52】astudybyhealth-policyanalys
In1993,amallsecuritycameracapturedashakyimageoftwo10-year-oldboysleadingmuchsmallerboyoutofaLiverpool,Engl
Nanotechnology,accordingtoitsfans,willjump-startanewindustrialrevolutionwithmolecular-sizedstructuresascomplexas
Inmostpeople’smind,growthisassociatedwithprosperity.WejudgehowwelltheeconomyisdoingbythesizeoftheGrossNat
Theyoungergeneration’sattractiontostereoscannotbeexplainedonly______familiaritywithtechnology.
Amidremarkableprogressoninflationandfiscalreform,Italyheadsinto1998withbrightprospectsforeconomicgrowthandits
随机试题
假设当前活动单元格在B2,然后选择了冻结窗格命令,则冻结了()
一位老年患者前来精神科门诊复诊。家属反映:该患者罹患精神疾病已20余年。最近患者出现一些怪异行为,比如:嘴唇徐动,时不时吐舌头,舔嘴唇,还常常做鬼脸,皱眉,眨眼。请问:该患者最有可能的诊断是
女性,28岁。胸闷、气短2周,伴乏力、低热,体温37.8℃,纳差,体检:一般情况好,浅表淋巴结不大,左肩胛下角线第8肋间以下语颤减低,叩诊浊音,呼吸音减低,腹部检查正常。其最可能的诊断为
女,45岁,近1年来盗汗、心悸、易怒,食量增加。检查:突眼,心率110次/分,血压126/84mmHg,甲状腺弥慢性肿大Ⅲ°,心律齐、无杂音,举手颤动明显。查血T3、T4高于正常值。诊为原发性甲亢,经抗甲状腺药物治疗后复发,拟行甲状腺双侧次全切除术。
仲裁过程中双方达成调解协议后:()
应独立设置,并伸出屋面的有()。
下列汇率风险管理方法中,通常成本较高的是()。
三级跳远技术中的第二跳,又叫做()。
例如:男:小王,帮我开一下门,好吗?谢谢!女:没问题。您去超市了?买了这么多东西。问:男的想让小王做什么?A开门√B拿东西C去超市买东西
Smartjobseekersneedtoridthemselvesofseveralstandardmythsaboutinterviewingbeforetheystartlookingforajob.What
最新回复
(
0
)